A connecting device of the above type commonly comprises firstly a securing element for securing it on to the wiper blade, and secondly a pivoting coupling element for articulation with a windshield wiper arm in such a way as to obtain a pivoted coupling between the wiper blade and the wiper arm. The securing element is arranged to cooperate with an opening or window which is provided on the blade, and more particularly on the back of the main stirrup which forms part of the carrier for the flexible wiping strip of the blade.
Such a connecting device, however, has a number of disadvantages in connection with the securing element which cooperates with the blade. For example, the window which is provided on the blade, and the securing element, are both manufactured with tolerances, which, when the latter comes into cooperation with the former, give rise to the likelihood that there will be a clearance between the securing element and the window.
Thus in operation, after being fitted to the wiper blade, the coupling element is loose with respect to the window. This gives rise to wear of the cooperating surfaces, and this wear in turn increases the clearance or play between the securing element and the window. When the wiper is in operation, this clearance involves discontinuity in the transmission of force, by setting up jumping or grazing of the wiping strip on the surface being swept. The latter is typically the windshield of an automotive vehicle. Such jumping or grazing not only causes disagreeable noises, but also poor quality of wiping which leads to poor visibility for the driver.
In addition, this wear takes the form of deterioration of the surfaces of the opening in contact with the securing element, by degradation of the coating or other surface treatment on the various surfaces, thus leading rapidly to corrosion of the latter. In addition, the window of the wiper blade is generally provided with a transverse axis or pin for locking the securing element on to the blade, and the provision of this axis involves an additional manufacturing operation on the blade, which thus increases its cost.